Coating machine for applying a fluid composition to a workpiece



Nov. 3, 1964 J. K. JACKSON 3,155,541

comma MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORKPIECE Filed May 29, 1961 5 Sheets-Sheet 1 FIG-/ INVENTOR JOHN K JAG/(JON 'MVZEW ATTORNEY Nov. 3, 1964 J. K. JACKSON COATING MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORKPIECE 5 Sheets-Sheet 2 Filed May 29, 196

Of/NKJACKSON I I ATTORNEY INVENTOR J.- K. JACKSON 3,155,541

Nov. 3, 1964 COATING MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORKPIECE 5 Sheets-Sheet 3 Filed May 29, 1961 WV N a I INVENTOR J /v lama/(501v -..L.:::.-' BY '7 i l 0 W w.:\\: ATTORNEY J. K. JACKSON 3,155,541 COATING MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORKPIECE Filed May 29, 1961 5 Sheets-Sheet 4 Nov. 3, 1964 INVENTO J HNK c/AC ON ATTORNEY Nov. 3, 1964 J. K. JACKSON COATING MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORKPIECE 5 Sheets-Sheet 5 Filed May 29, 1961 FIG 6 INVENTOR ATTORNEY United States Patent 3,155,541 CGATING MAQHINE FOR APPLYING A FLUID COMPOSITIUN T0 A WGRKFIECE John K. Jackson, 671 (Iarleton Road, Westfield, NJ. Filed May 29, 1% Ser. No. 113,434 4 Claims. (Cl. 118-203) The present invention relates to machines for the liquid coating of various types and kinds of articles or members, wherein the articles are delivered by a continuous infeed conveyor and then fed through one or more machines to provide one or more liquid coatings thereon. The machine is particularly suitable for the application of one or more liquid coatings to workpieces such as ceramic tile, structural brick, cinder blocks, panels, flat plates, or the like for the glazing thereof.

Generally, the glaze coating of such materials is done commercially by the use of compressed air spray guns positioned over the work pieces on a conveyor belt, the surplus coating material being collected in a subtank, and a hood and a stack being used to remove overspray. The coating material collected in the subtank is recirculated through the compressed air spray guns and thus there is considerable evaporation resulting in a change in the solid/liquid ratio due to decrease in the liquid content causing difiiculty in maintaining the glaze composition at a proper constant viscosity. It is quite important that the viscosity be kept constant as otherwise the shade of the glazed work piece will vary. However, it should be kept in mind that to be practical the cost of the glazed work piece must be kept as low as possible for successful commercial sales.

The spray processes heretofore used have not been uniform in the application of the composition primarily because it is impossible to properly adjust the spray nozzles to follow the variations in the viscosity of the coating composition, resulting from the evaporation losses.

Another difficulty with the spray coating is that surface defects and pin holes in the work pieces are not filled resulting in a glaze surface having in many cases a pockmarked appearance. Furthermore, the use of a spray presents an inherent difficulty in that the mixture of the air propellant with the glaze introduces irregularities such as minute air bubbles which sometimes cause distortion of the glazed surface. Another difficulty had with the spray apparatus is the difiiculty in changing from a glaze of one color to a glaze of another color in that the conveyor belt and tanks require clean up time requiring several man hours of labor. 1

Other disadvantages in the use of the spray are in the losses resulting from overspray in that excesses of glaze material, must be discharged over a large area to provide coverage for the work pieces of a considerably smaller area. In addition spray apparatus requires the use of hoods with the resultant considerable stack losses.

It is important in applying a glazed coating to some materials to apply a primary coat. In the case of porous material the primary coat provides a seal in preparation for a final coat such as in the case of the material having a pin-holed surface or the like in which event the primary coat provides a smooth basis for the final coat. The conventional spray machine is incapable of applying more than one formulation of coating material inasmuch as the conveyor belt passes over the subtank and thus would contaminate the next subtank.

The present invention aims to overcome the foregoing difiiculties and disadvantages by providing acoating machine which accurately applies a composition to the material to be coated without overspray or-vapor losses and with an even thickness of composition.

In accordance with the invention this is accomplished Ice by utilizing a source of supply to feed a metering roll which picks up a predetermined amount of coating and applies same to a coating roll, the coating roll having an absorbent characteristic to withdraw a metered amount of composition from the metering roll and transfers it to the work piece.

In accordance with a further step of the invention means are provided for readying the absorbent coating roll so that it is prepared to absorb a predetermined amount of composition from the metering roll irrespective of whether the composition previously applied to the coating roll has been deposited on a work piece. The machine in accordance with the invention is advantageou in that a plurality of machines may be operated in tandem, the first machine may be used to apply a precoat to prepare the surface or" the work piece, the additional machines being used to apply one or more coating for various purposes.

The machine in accordance with the invention is further advantageous in that there is no loss corresponding to the overspray loss resulting from the use of the spray machine and which is a minimum of fifty percent. Additionally there is no stack loss as is the case with the use of the spray machine and which is between fifteen and twenty percent loss.

Still further, the color change down time for the liquid coating machine is about thirty minutes while the color changed down time for a spray machine is about six hours.

In addition it has been found that on the use of the liquid coating machine no pin holes, bubbles, or surface imperfections resulting from the glaze application are present, as occur, in many cases, when a spray machine is used.

Another object of the invention is to provide a coating machine which is simple and economical in maintenance, efficient in operation and durable in use.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawings which show, by way of example, an embodiment of the invention.

In the drawings FIGURE 1 is a schematic showing of a plurality of coating machines constructed in accordance with the invention and in position along a conveyor belt line.

FIGURE 2 is a plan view of one of the coating machines shown on the assembly line of FIGURE 1.

FIGURE 3 is a side view of one of the coating machines.

FIGURE 4 is a sectional view taken along the line 44 of FIGURE 2.,

FIGURE 5 is an enlarged fragmentary view of a portion of FIGURE 4.

FIGURE 6 is a sectional view taken along the line 65 of FIGURE 4.

Referring to the drawings there is shown in FIGURE lan installation 1 including a pair of coating machines 2 and 3 which may be supplied from a common composition supply 5. Obviously separate sources of supply may be provided for the machines 2 and 3 if desired.

The work piece to be coated may be discharged fromany conventional processing machinery and transmitted over the conveyor belt section 6 shown as partially broken away. As an illustration of work pieces to be coated there are shown tiles 7 on the conveyor belt 6 and on dead plates 9. I

The coating machines 2 and S may be identical and each includes a composition reservoir 10 supplied by a pipe 11 in fluid communication through a pipe 12 with the common supply tank 5. It should be noted that a definite supply level is maintained in the glaze composition reservoir It) by terminating supply pipe 11 at the desired fluid level as indicated at'14. The coating machine 2 includes a reservoir 15, a fountain or supply roll 16, a metering roll 17, a coating roll 18, and a doctor blade 20.

The reservoir 15 is supplied with composition from the composition reservoir by a circulating pump 21 through a feed pipe 22, any overflow being returned to the composition reservoir 10 by a pipe 24. In addition a pipe 25 returns surplus composition to the reservoir from the vicinity of the doctor blade 20.

Referring to FIGURE 4 there is shown a cross sectional view of the coating machine 2. By reason of the rotation of the supply roll 16 fluid is transferred to the surface of the metering roll 17 and thence to the surface of the coating roll 19 for application to the work pieces such as the tiles 7. The surface of the coating roll 19 is made ready to receive additional composition from the metering roll 17 by reason of the action of the doctor blade 20 in removing excess composition. In the event there is no work piece in position to receive the composition, the doctor blade 29 clears away the composition so that there is no excess composition for the next work piece. The rotation of the various rollers 16 through 19 is achieved by gearing as may be seen in FIGURE 3.

The supply roll 16 includes a core member 26 having its surface rubber coated as indicated at 27. The core 26 may be made integral with its supporting shaft 29 which is journalled in adjustable bearings 30, fabricated in a conventional manner, and whose purpose is to provide an adjustment of the contact pressure between the surfaces of the supply roll 16 and the metering roll 17. The surface of the rubber coating 27 of the supply roll 16 is ground smooth to provide an accurate surface.

The metering roll 17 has its surface 31 (FIGURE 5) engraved or otherwise treated to provide a plurality of recesses or cavities 32 of a predetermined cubic storage capacity. The cavities may be made in any suitable manner well known in the art. The metering roll 17 may be made integral with its shaft 34 which is carried in adjustable bearings 35.

The coating roll 19 includes a core member 36 fitted with a removable absorbent coating cylinder 37. The core 36 may be made integral with a shaft 39 for support in a removable assembly 49 shown in detail in FIGURE 6, and which includes housing ends 41 and 42 to which are attached coating-roll mounting brackets 44 and 45, each having flanged ends 46 and 4-7 attached to flanges 43 and 49 of the housing ends 41 and 42 by screws 59.

he coating roll mounting brackets 44 and are held in spaced relationship by a rigid cross member 51, the coating roll mounting brackets 44 and 45 being removably attached thereto by screws 54. At the inner ends of the coating roll mounting brackets 44 and 45 are bearings and 56, against which are pressed collars 57 and 59 by springs 60 and 61. At one end of the shaft 39 is a gear 62 frictionally held in position by a screw 64 hearing against a washer 65. The shaft 39 carries another gear 66 positioned between the coating roll mounting brackets 45 and the housing end 42. The springs 60 and 61 press disc members 67 and 69 against the ends of the cores 36 thereby holding the coating cylider 37 in place.

The doctor blade 2!) (FIGURE 4) is attached to a supporting shaft 79 by screws 71 (FIGURE 2) or by other conventional means. At the ends of the shaft 7t) are set screw collars 72 and 7 3-, the out r ends of the shaft 7% being journalled in bearings not shown. The degreeof angular rotation of the doctor blade 20 may be shown by an index pointer 75 cooperating with a scale 76 on the collar 74, the shaft'l't' being locked in a desired position by a set screw 77.

The supply roil 16, the metering roll 17, and the coating roll 19 are rotated by gears 86, 81, and 66 (FI URE 3). The gears and 81 are respectively positioned at the ends of the shafts 29 and 34 in the housing 83.

The gear 66 (FIGURE 2) is driven throughthe 4- idler gear 8 3 driven by unit drive gear 85'. The unit drive gear 85 is in mesh with a gear 86 (FIGURE 3) having a sprocket 87 driven by a chain 89 in turn engaging a. sprocket 99 on a belt pulley shaft 91 carrying a belt pulley 92.

A bed 190 may be attached in any suitable manner to supporting means to position the assembly of the coating machine above the conveyor belt 6. At one end of the bed 100 is a journal 161 (FIGURE 3) secured in position by screws 162 for the support of the shaft 91. The bed 100 also carries on its under side a journal 104 for the support of a shaft 105 carrying the sprocket 37, the journal 104 secured in position by bolts 106. On the upper side of the bed 100 opposite to the journal 104 is another joumal 157 for a shaft 109 for the unit drive gear 85. The shaft 109 is also a pivot point for the support of the housing ends 41 and 42 (FIGURE 2). On the housing ends 41 and 42 are bosses 119 (FIGURE 3) which are adapted to respectively ride on eccentrics 111 and 112 (FIGURE 6) fixedly attached to a shaft 114 carried by a journal 115 positioned on the underside of the bed 1% and secured thereto by screws 117. At the end of the shaft 114 is an adjustment knob 119 carrying a dial indicator 120. The degree of eccentricity of the eccentrics 111 and 112 is such that they will remain in place once set without the necessity of locking means although locking means may be provided if desired. By using the shaft 114 as a pivot point the housing ends 41 and 42 may be raised or lowered (FIG- URE 3) carrying therewith the coating roll 19 (FIGURE 4-) and thereby adjusting the height of its coating cylinder 37 above the bed 190 thus providing for a variation in the degree of pressure agm'nst the surface of a work piece 7.

The trough 122 (FIGURE 4) is inclined in the direction of and in fluid communication with the pipe 25 to receive surplus composition removed by the doctor blade 29.

Also carried by the housing ends 41 and 42 as a journal is a shaft 125 for the pivotal support of side walls 126 and 127 carrying the assembly of the supply roll 16 and the metering roll 17. Means are provided for the relative positioning of this assembly to adjust the contact pressure between the metering roll 17 and the coating roller 1), and for the separation of these parts when the coating operation is not being performed. This means includes a throw lever 129 (FIGURE 3) having a knob 131? at its end, the lever 129 extending from a cam memer rigidly attached thereto and rotatable on tie or 132, the tie bar 132 extending between the sidewalls 26 and 127. In juxtaposition with the tie bar 132 is an oppositely positioned tie bar 134 extending between the housing end 5-1 and 42. The tie bars 132 and 134 are drawn together by a strong spring The tie bar 134 (FTGURE 4) carries a manual adjustment screw 137 having a knob 13), end 148 of the screw 137 abutting against the tie bar 132. The spacing between the tie bars 132 and 13 5 which controls the contact between the metering roll 17 and the coating cylinder 37 is made by adjusting the knob A lock nut 141 maintains the adjustment once it has been made.

The metering surface 31 of the roll 17 is formed with cavities thereon to accurately meter the amount of fluid composition taken up from the supply or fountain roller surface 2'7. The fountain roller surface 27 Sup plies a surplus of material to the metering surface 31 which flushes the cavities 32 of any material therein and refills the cavities Any surplus material is squeeged off and drops back into the reservoir 15, there being suf ficient pressure contact between the surface 27 of the so; ply roll and the metering surface 31 to effect the sau eegeeing action, and to eliminate any surface film and thus confine the material to be coated inthc cavities 32 of the metering roll. The cavities 32 may be of any desired size ranging generally from a screen size with a diagonal count from 5 to 100 cavities per inch, desirably from 7 to 20 cavities per inch. The preferred surface of the metering roll depends upon the formulation and quantity of the composition to be coated. If the cornposition is of low viscosity a larger screen size with less cavities per inch is preferred. If the composition is of a higher viscosity a greater number of cavities per square inch is preferred. Funther, the more pressure contact had between the metering and the coating rolls, the greater is the amount of the coating material that is removed from the metering roll, within limits. By reducing the con-tact the amount of material absorbed by the coating cylinder is reduced. The contact reduction is accomplished by the manipulation of adjustment knob 159. Another control which varies this condition is the degree of pressure of the doctor blade against the coating cylinder 37.

The depth of the cavities 32 ranges between 0.001 and 0.050, desirably between .010 to .030, depending on the composition of the material to be coated.

The coating cylinder 37 is preferably made with an inside diameter sufficiently smaller than the outside diameter of the core member 3% so as to maintain the cylinder 37 in position and eliminate slippage thereof on the core 36. The outside circumference of the coating cylinder 37 should be such that its peripheral speed is equal to or somewhat less than the linear travel of the belt conveyor. This is important in order to prevent an accumulation of coating material which would over flow on to the trailing edge of the work piece.

- The coating cylinder 37 is made from a suitable absorbent material having interconnecting cells such as foam rubber or foam plastic. The absorbent quality of this material should be considerable. For example, a cylin der made of felted cot-ton or cotton cloth probably would not have enough absorbency to achieve the desired results. A smooth rubber coating would be impractical because it would only transfer the surface film from the metering roll to the coating cylinder. In order to apply suilicient coating material to the work piece it is necessary to have a controlled constant quantity of the coating material in the cavities 32 of the coating roller 1'7, and by pressure contact with the absorbent roll 37 to transfer a predetermined desired amount of this material from the metering roll cavities 32 to the workpiece. In order to achieve this result the absorbent roller 37 must remove the coating material from the cavities 32 by an absorption or suction action.

7 It should be kept in mind that the doctor blade 20 conditions the absorbent roller 37 by pressure action thereagainst which squeegees out of the absorbent roller 37 any composition absorbed therein, and, of course, wipes the surface of the absorbent roller 37 clear of any composition thereon. Thus, the absorbent roller 37 al ways presents a surface to the metering roll If) of the same predetermined absorbent quality. It should be noted that the action of the absorbent roller 17 in transferring a predetermined amount of coating from the metering roll 17 to the workpiece 7 differs from a printing operation. The transfer of ink in a printing operation from the plate cylinder to the printed surface is achieved by applying a predetermined amount of ink to the surface of the plate cylinder. Inasmuch as the surface of the plate cylinder is always non-absorptive the ink is carried on the surface. In coating work pieces with glazing and/or other compositions the plate cylinder of the printing macihne would not be effective because of the limited amount of material which would be transferred by the plate cylinder.

Compositions which have been found particularly suit able for the absorbent cylinder or roll 37 are foam plastic cylinders cut from foam plastic sheets of suitable density having interconnecting cells of suitable cell size.

The density and cell size of the absorbent material is selected after experiment with the characteristics of tne composition to be coated. Generally speaking an absorbent material having a weight of from one to 6 pounds per cubic foot and a cell count from 20 per inch to per inch is satisfactory.

it should be noted that the contact pressure between the absorbent surface 37 of the coating roll 19 against the surface of the metering roll 17 is variable. Thus the efiicieucy with which the absorbent surface 37 removes the liquid coating composition from the cavities 32 depends upon the amount of contact pressure. The surface 37 is described as being absorbent, and the meaning of this word is intended to be that the material has small interconnected cavities to receive the liquid composition from the cavities 32 and transfer the liquid to the work pieces 7.

The hardness of the fountain roll 27 is of some importance. If it is too soft, pressure contact between the fountain roll and the metering roll would cause a deformation of the surface of the fountain roll which results in a scavenging action in the cavities of the metering roll. The hardness of the fountain roll should be such that using sufficient pressure to cause approximately .002 to .005 inch compression of its surface at the point of contact with the metering roll, the surface of the metering roll will be properly squeegeed and its surface would have no surface film and all of its cavities would be filled properly. The range of rubber hardness may be stated as of approximately 50 to 60 durometer. A satisfactory thickness of the rubber coating 27 on the fountain roll 26 has been determined by experiment to vary between and /2".

The absorbent coating cylinder 37 has an approximate thickness of /2 to This has been found satisfactory since it will hold an adequate surplus of coating material which can be controlled. The amount of material applied to the work piece is controlled by the degree of the doctoring action in preparing the absorbent roll, the composition of the coating cylinder, the amount of coating material available on the metering roll, the degree of pressure contact between the metering roll and the absorbent coating roll, and the degree of pressure contact between the absorbent coating roll and the work piece.

It has been found preferable to arrange the peripheral speed of the coating roll 37 to be equal to or somewhat slower than the linear speed of the work pieces 7, preferably the peripheral speed of the coating roll 37 should be two to five percent slower than the speed of the workpiece 7. It has been found that when the coating cylinder and the work piece travel at the same rate of speed there is a head of surplus coating material which accumulates at the trailing edge of the contact therebetween, the beam increasing in magnitude as the rotative speed of the coating cylinder is increased with respect to the linear speed of the workpiece. However, by reducing the rotative speed of the coating cylinder with respect to the speed of the work piece the head is eliminated. The disadvantage of the bead is that it runs down the back edge of the work piece resulting in an objectionable appearance of the work piece and in an increase in its length.

In the operation of the coating machine it is set in position above a conveyor belt carrying workpieces 7. The fountain roll 27 is brought into proper contact pressure with the metering roll 17 by manipulating the adjustable bearings 30 at the end of the fountain roll shaft 29. The contact pressure is adjusted so that all surplus material is squeegeed back into the reservoir 15 yet the cavities 32 in the surface of the metering roll 17 contain a full supply of coating material.

The metering roll 17 is brought into proper pressure contact with the coating roll 37 by adjusting the screw 137 by turning its knob 13? so that a metered amount of coating material is removed from the cavities 32 during each revolution of the coating roller, this amount being slightly in excess of the amount required for the coating on the work piece.

The doctor blade 20 is brought into contact with the surface of the coating roll 37 to doctor off the surplus applied by the metering roll 17.

When the adjustment is made so that the coating roll 37 is sufficiently saturated with coating material on each revolution it is lowered into pressure contact with the workpiece 7. The amount of compression of the coating roll 37 by the workpiece 7 is adjusted by manipulating the knob 119.

The amount of coating material contained in the coating roll 3-7 is a controlled quantity for each revolution thereof irrespective of whether or not a work piece is present to be coated. In the event a work piece is present a desired amount of coating material is dispensed thereon and the surplus is removed by the doctor blade 25) as it conditions the coating roll 37 for a fresh application of the desired amount of coating material by the metering roll 17. In the event no work piece is present, the doctor blade 26 removes the coating material which would have been deposited thereon. the coating roll 37 there is a fresh metered quantity of coatin material thereon ready for application to a work piece. This permits feeding of the work pieces at random intervals.

While the invention has been described and illustrated with reference to a specific embodiment thereof, it will be understood that other embodiments may be resorted to without departing from the invention. Therefore, the form of the invention set out above should be considered as illustrative and not as limiting the scope of the following claims.

I claim:

1. A coating machine for applying a fluid composition to a work piece comprising a metering roll having cavities on its surface of a predetermined to receive the fluid composition, a coating roll, means to rotate the metering and coating rolls, and a doctor blade in pressure contact with the coating roll to control the amount of unused coating composition carried thereby and to condition the coating roll for a supply of coating from the metering roll, the coating roll having an interconnecting absorbent cellular structure in rotatable pressure contact with the metering roll to receive a predetermined amount of fluid composition therefrom mainly by suction action, the coating roll adapted to dispense a metered quantity of the fluid composition to the surface of a workpiece upon pressure contact therewith.

2. A coating machine for applying a fluid composition to a work piece comprising a metering roll having cavities on its surface of a predetermined size to receive the fluid composition, a coating roll, means providing pressure contact between the metering and coating rolls, means to rotate the metering and coating rolls, means for controlling the pressure contact between the metering and coating rolls, a doctor blade in pressure contact with the unused coating roll to control the amount of coating composition carried thereby and to condition the coating roll for a supply of coating from the metering roll, means for controlling the pressure contact between the doctor blade and the coating roll, and means for controlling the pressure between the coating roll and the work piece, the coating roll having an interconnecting absorbent cellular structure in pressure contact with the metering roll to receive a predetermined amount of fluid composition therefrom mainly by suction action, the coating roll adapted to dispense a metered quantity of the fiuid composition to the surface of a workpiece upon pressure contact therewith.

3. A coating machine for applying a fluid composition to a work piece comprising a supply roll, a metering roll having cavities on its surface to receive a predeteri -ined amount of the fluid composition from the supply roll, a coating roll having a flexible interconnecting absorbent cellular structure, means to rotate the supply, metering and coating rolls, means providing pressure contact be- Thus for each revolution of tween the metering and coating rolls, means for controlling pressure contact between the supply and the metering rolls, first frame means supporting the supply and metering rolls, first pivotable supporting means for the first frame means, second frame means supporting the coating roll and carrying the first pivotable supporting means for the first frame means, second pivotable supporting means for the second frame means, a bed carrying the second pivotable supporting means, first frame positioning means operative to rotatively move the first frame means about its pivot and thus vary pressure contact between the metering and coating rolls, second frame positioning means operative to rotatively move the second frame means about its pivot and thus vary pressure contact between the coating roll and a workpiece, a doctor blade carried by the second frame in juxtaposition to the coating roll, doctor blade adjustment means operative to move the doctor blade against the coating roll to vary pressure contact therewith and thus control the amount of unused coating composition carried thereby and to condition the coating roller for a supply of coating from the metering roll.

4. A coating machine for applying a fluid composition to a work piece comprising a supply roll, a metering roll having cavities on its surface to receive a predetermined amount of the fluid composition from the supply roll, a coating roll having a flexible interconnecting absorbent cellular structure, means to rotate the supply, metering and coating rolls, means providing pressure contact between the metering and coating rolls, eccentric means for controlling pressure contact between the supply and the metering rolls, first frame means supporting the supply and metering rolls, first pivotable supporting means for the first frame means, second frame means supporting the coating roll and carrying the first pivotable supporting means for the first frame means, second pivotable supporting means for the second frame means, a bed carrying the second pivotable supporting means, screw means between the first and second frame means operative to rotatively move the first frame means about its pivot and thus vary pressure contact between the metering and coating rolls, eccentric second frame positioning means operative to rotatively move the second frame means about its pivot and thus vary pressure contact between the coating roll and a work piece, a doctor blade carried by the second frame in juxtaposition to the coating roll, doctor blade adjustment means operative to move the doctor blade against the coating roll to vary pressure contact therewith and thus control the amount of unused coating composition carried thereby and to condition the coating roll for a supply of coating from the metering roll, and means for moving a work piece past the coating roll, the linear speed of the work piece greater than the peripheral speed of the surface of the coating roll.

References Qited in the file of this patent UNITED STATES PATENTS 229,785 Whitney July 6, 1880 346,894 Case Aug. 10, 1886 728,793 Dunn May 19, 1903 1,177,351 Murray Mar. 28, 1916 1,331,460 Morrison Feb. 17, 1920 1,501,048 Hampson July 15, 1924 1,505,398 McEachron Aug. 19, 1924 2,156,286 Harshberger May 2, 1939 2,213,117 Blackmore Aug. 27, 1940 2,293,690 Harrigan Aug. 18, 1942 2,329,034 Buck et a1 Sept. 7, 1943 2,428,113 Grupe Sept. 30, 1947 2,545,539 Belluche et al Mar. 20, 1951 2,582,407 Barrett et al. Jan. 15, 1952 2,749,878 Hagen June 12, 1956 2,804,678 Rockoff Sept. 3, 1957 

1. A COATING MACHINE FOR APPLYING A FLUID COMPOSITION TO A WORK PIECE COMPRISING A METERING ROLL HAVING CAVITIES ON ITS SURFACE OF A PREDETERMINED SIZE TO RECEIVE THE FLUID COMPOSITION, A COATING ROLL, MEANS TO ROTATE THE MERTERING AND COATING ROLLS, AND A DOCTOR BLADE IN PRESSURE CONTACT WITH THE COATING ROLL TO CONTROL THE AMOUNT OF UNUSED COATING COMPOSITION CARRIED THEREBY AND TO CONDITION THE COATING ROLL FOR A SUPPLY OF COATING FROM THE METERING ROLL, THE COATING ROLL HAVING AN INTERCONNECTING ABSORBENT CELLULAR STRUCTURE IN ROTATABLE PRESSURE CONTACT WITH THE METERING ROLL TO RECEIVE A PREDETERMINED AMOUNT OF FLUID COMPOSITION THEREFROM MAINLY BY SUCTION ACTION, THE COATING ROLL ADAPTED TO DISPENSE A METERED QUANTITY OF THE FLUID COMPOSITION TO THE SURFACE OF A WORKPIECE UPON PRESSURE CONTACT THEREWITH. 